Ball-joint cap: Ø40 × 8 ring with an R15 spherical seat and 3 × Ø3.4 holes — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/ball-joint-cap-d40-r15/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Xem Studio design following Brown's figure (1868); true size, no printing allowance
Catalog version: 2026-10-20

Overall (mm): length 40.0, width 40.0, height 8.0
- Ø40 × 8 ring whose bore is the R15 sphere between z 0 and 8 (opening Ø25.38 at the top, smaller than the Ø30 ball), so screwed down on the socket it holds the ball in; three Ø3.4 holes for M3 screws.
- Xem Studio design following Brown's figure; true size, no printing allowance (apply your own to the mating features).

dimension  value
ring  Ø40 × 8
seat  R15 sphere
opening  Ø25.38
holes  3 × Ø3.4 on Ø32

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Henry T. Brown (1868, public domain): Five Hundred and Seven Mechanical Movements — scan on archive.org — web — Publisher's page; dimensions are facts — https://archive.org/details/fivehundredseven00browiala
- 507movements.com: Brown's movement No. 249: figure, his text and an animation — web — Publisher's page; dimensions are facts — https://507movements.com/mm_249.html
- Xem Studio: drawing — web — Publisher's page; dimensions are facts — https://xemstudio.com/objects/tube-ball-and-socket-joint-mechanism/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/ball-joint-cap-d40-r15/index.json
API: https://xemstudio.com/api/geometry?object=ball-joint-cap-d40-r15